I need to build Unified Modeling Language (UML) Diagram Can someone help me?

Instructions and requirements are down below.

This is what i have so far

 

Requirements: Human Resource/Staffing System HRCO is a small staffing firm that matches applicants to job openings. Companies will use HRCO's site to submit details about job openings they have available. Candidates who are seeking jobs will submit their details and upload their resumes onto this system. Candidates can also select specific job postings listed and send their application to those postings. Companies can search for applicants that match their job opening requirements. Candidates can also search for open positions. HRCos employees should be able to generate various types of reports. For example, they should be able to generate a report that shows the applicants who have gotten offers during a particular period of time and with the details about the companies that have made offers to these applicants. Companies can also generate a variety of reports, as for example the total number of candidates that applied for company positions, and the percent that were offered the job.